title: Coffee, alcohol, smoking, physical activity and QT interval duration: results from the Third National Health and Nutrition Examination Survey.
abstract: BACKGROUND
  Abnormalities in the electrocardiographic QT interval duration have been associated with an increased risk of ventricular arrhythmias and sudden cardiac death. However, there is substantial uncertainty about the effect of modifiable factors such as coffee intake, cigarette smoking, alcohol consumption, and physical activity on QT interval duration.
  
  
  METHODS
  We studied 7795 men and women from the Third National Health and Nutrition Survey (NHANES III, 1988-1994). Baseline QT interval was measured from the standard 12-lead electrocardiogram. Coffee and tea intake, alcohol consumption, leisure-time physical activities over the past month, and lifetime smoking habits were determined using validated questionnaires during the home interview.
  
  
  RESULTS
  In the fully adjusted model, the average differences in QT interval comparing participants drinking ≥6 cups/day to those who did not drink any were -1.2 ms (95% CI -4.4 to 2.0) for coffee, and -2.0 ms (-11.2 to 7.3) for tea, respectively. The average differences in QT interval duration comparing current to never smokers was 1.2 ms (-0.6 to 2.9) while the average difference in QT interval duration comparing participants drinking ≥7 drinks/week to non-drinkers was 1.8 ms (-0.5 to 4.0). The age, race/ethnicity, and RR-interval adjusted differences in average QT interval duration comparing men with binge drinking episodes to non-drinkers or drinkers without binge drinking were 2.8 ms (0.4 to 5.3) and 4.0 ms (1.6 to 6.4), respectively. The corresponding differences in women were 1.1 (-2.9 to 5.2) and 1.7 ms (-2.3 to 5.7). Finally, the average differences in QT interval comparing the highest vs. the lowest categories of total physical activity was -0.8 ms (-3.0 to 1.4).
  
  
  CONCLUSIONS
  Binge drinking was associated with longer QT interval in men but not in women. QT interval duration was not associated with other modifiable factors including coffee and tea intake, smoking, and physical activity.
authors.affiliation: Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, United States of America.
authors.forename: Yiyi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Wendy S
authors.initials: WS
authors.lastname: Post
authors.forename: Darshan
authors.initials: D
authors.lastname: Dalal
authors.forename: Elena
authors.initials: E
authors.lastname: Blasco-Colmenares
authors.forename: Gordon F
authors.initials: GF
authors.lastname: Tomaselli
authors.forename: Eliseo
authors.initials: E
authors.lastname: Guallar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking; D001628:Beverages; D003069:Coffee / Q000009:adverse effects; D004327:Drinking Behavior / Q000502:physiology; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009749:Nutrition Surveys; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D013662:Tea; D013997:Time Factors; D014481:United States; D055815:Young Adult
chemical_list: D003069:Coffee; D013662:Tea